Question

A page of Passbook of Mrs. C. Malik Savings Bank Account in year 2002 is given below:

Date Year 2002	Particulars	Amount Withdrawn (in ₹)	Amount Deposited (in ₹)	Balance (in ₹)
Jan. 1	By Balance	-	-	2,100·00
Jan. 7	By Cash	-	1,000·00	3,100·00
Feb. 1	By Cash	-	500·00	3,600·00
Feb. 15	To Cheque	2,000·00	-	1,600·00
March 15	By Cash	-	2,000·00	3,600·00
March 20	To Cheque	1,000·00	-	2,600·00
June 12	By Cash	-	3,000·00	5,600·00
June 28	To Cheque	1,000·00	-	4,600·00
Oct. 15	To Cheque	3,000·00	-	4,600·00
Nov. 5	By Cash	-	1,500·00	3,100·00
Dec. 10	By Cash	-	500·00	3,600·00
Dec. 20	To Cheque	1,000·00	-	2,600·00

If the rate of interest decreases from 5% to 4% with effect from June 1st, 2002, compute the interest at the end of the year.

Answer 1

As per entries of the Passbook page of Mrs. C. Malik, we have:

Month	Minimum Balance between 10th day and the last day (in ₹)	Qualifying Amount for interest (in ₹)
Jan.	3,100	3,100
Feb.	`{:(1600),(1600):}}`	3,200
March
April	`{:(2600),(2600):}}`	5,200
May
June	2,600	2,600
July	`{:(4600),(4600),(4600):}}`	13,800
Aug.
Sept.
Oct.	1,600	1,600
Nov.	3,100	3,100
Dec.	2,600	2,600

Qualifying amount for interest at the rate of 5 % = ₹ 11,500.      .....(from January to May)

∴ Interest = ₹`(11,500 xx 5 xx 1)/(100 xx 12) = ₹ 47.92`

Qualifying amount for interest at the rate of 4% = ₹ 23,700.     ...(from June to December)

∴ Interest = ₹`(23,700 xx 4 xx 1)/(100 xx 12) = ₹ 79`

∴ Interest at the end of the year = ₹ 47.92 + ₹ 79 = ₹ 126.92